Having tooth removed; is it painful? FAQ's?

I didn't know that I haven't been in so long, because i didnt get a notice, but apparently i haven't been to the dentist in a year. I'm 16 and I have an abcess (infection) on my wisdom tooth. I think that's what it's called? it's the 2nd back tooth at the top. There's a hole at the side, and I have been having EXTREMELY painful toothaches recently. My tooth removal appointment was in 2 weeks due to NHS (i dont have to pay) but because it is soooo paainful, i'm paying for the extraction and so the appoointment has been moved and its getting removed in 2 days. I am kinda scared, :/ How long does the process take? Is it kinda painful? Before i went to the dentist, she gave me amoxicillin capsules (antibiotics). It's to get rid of the infection. When i have my tooth removed, do i finish the course? I have to eat it 3 times a day for one week. Once the tooth is extracted, i have 3 days left to finish the course. Also, is there anything you need to prepare? I don't know if anyone else has felt this, but because the toothache was hurting so much, the bottom left side of my teeth started to hurt as well........consisting throbbing stabbing pain...... the toothache hurts MOST at night, and i cant sleep. What happens after the tooth extraction? Does your teeth still hurt, is it still painful?